Water-soluble monoazo pyrazolone dyestuffs



Unifted Patent-Office 3,406,163 Patented Oct. 15, 1968 3,406,163WATER-SOLUBLE MONOA-ZO PYRAZOLONE DYESTUFFS Fritz Meininger and AugustBauer, ,Frankfurt. -am Main,

and Klaus Berner, Hofheim, Taunus, Germany, assig'nors to,FarbwerkeHoechst, Aktie'ngesellsc'haft vor mals Meistr Lucius &-Brjuning, Frankfurt am Main,

'Germany,-a corporation of -Ge'rm'any Q "No Drawing. Filed Apr'. 26;1965, Ser. No.- 451,047

The present invention provides new water soluble monoazo-dyestutfs and aprocess for preparing them; it provides in particular water-solublemonoaza-dyestulfs which in the form of their free acids correspond tothe formula S 0 CH CH QSOaH- in which nrepresents the integers 0, 1 or 2and A is lower alkyl. 50

It has been found that valuable, very easily water-solublemonoazo-dyest'uifs which in their free acids correspond to the formulaSOQH aikyl, can be prepared by diazotising an amine of the formula Irams) by coupling itwith a pyrazolone derivative'of the formula o- 0 amo" o--A O=C'.N O=C.-N

S O2CHrCHi-OSO:tH S O2CH2CHzOH HY; wherein n and A have the meaningsindicated above, and by esterifying in the known manner the hydroxylgroup of the hydroxyethylsulfone radical with concentrated sulfuric acidor an agent yielding sulfur trioxide, As diazo components the followingamino compounds may be used: Z-naphthylamine-l-sulfonic acid,Z-naphthylamine-l.5-disulfonic acid, Z-naphthylamine-1.6-disulfonicacid, Z-naphthylamine-l.7-disulfonic acid and 2-naphthylamine-1.5.7-trisulfonic acid.

It is suitable to carry out the esterification by introducing thestarting dyestulfs obtained by coupling the diazotised amino compoundswith pyrazolones of the Formula II, into concentrated sulfuric acid andstirring at the usual temperature until completely dissolved. Theconversion of the starting dyestulfs into the corresponding sulfuricacid esters may also be carried out by reacting the hydroxyl group ofthe hydroxyethylsulione radical with an agent yielding sulfur trioxide,such as chlorosulfonic acid or amidosulfonic acid, in an inert organicsolvent. Appropriate solvents are forexample-dimethylformamide,dimethylsulfoxide, quinoline, dimethylaniline, pyridineor homologues ofpyridine as for example picoline.

Pyrazolones of the Formulae I and II used as coupling components can beobtained by reacting in the usual manner the corresponding derivativesof phenylhydrazine with aceto-acetic esters or diketene and if requiredby esterifying subsequently the hydroxyl group of thehydroxyethylsulfone radical in accordance with the esterificationprocess described above.

The monoazo-dyest-utfs obtained according to the proc ess of the presentinvention, are valuable as regards the dyeing of cellulose textiles, forexample cotton, 'linen and viscose rayon. They may be used according totechnically common dyeing and printing processes for reactive dyestuffsand they produce in the presence of agents having an alkaline reactionon cellulose materials greenish yellow tints of very good .fast-ness tolight and washing.

The special value of the new dyestuifs resides in the fact, that in thedyeing of native and regenerated cellulose fibers particularly from longbaths, the dyeing baths are exhausted very well and that dyeings andprints of agood depth of color are obtained, which are disting'uished byevenness of shade and very good fastness properties, particularly byexcellent fastness to light.

' As regards building up and color strength ,of cotton dyeings as wellas light fastness, the monoazo-dyestutfs obtained according to theprocess of the present invention are far superior to themonoazo-dyestuifs disclosed in US. Patent 2,728,762 and most comparableto the abovementioned dyestulfs.

The following examples serve to illustrate the inven- EXAMPLE 1 151.5parts of Z-naphthylaminel.S-disulfonic acid are diazoti-sed in the usualmanner. 141 parts of 1-(4'-B-hydroxyethylsulfonylphenyl)-3-methyl-5-pyrazolone are introduced into the aqueous suspension of thediazonium salt. The coupling mixture is neutralised by addition ofsodium carbonate and stirred until the dyestuff has formed. The yellowmonoazo-dyestuff obtained is precipitated with potassium chloride,filtered oh and pulverised after the drying at temperatures of 70 to 80C.

To convert the dyestuff thus obtained into the sulfuric acid ester, thedyestuff powder is introduced into 2000 parts of concentrated sulfuricacid and the whole is stirred overnight at room temperature. Thereaction mixture is then added to 4000 parts of ice powder. The dyestuffis salted out by addition of potassium chloride, filtered ofi, washeduntil neutral with potassium chloride solution of of weight and dried attemperatures of 50 to 60 C. in a vacuum drier. 453 parts of a yellowpowder, which dissolves in water producing a yellow color, are obtained.

In the form of its free acid, the dyestufi corresponds to the followingformula:

SOsH

In the presence of alkalis the dyestuif produces in saltcontainingdyeing baths on native and regenerated cellulose fibers full, clear,greenish yellow dyeings exhibiting very good fastness to wetting andlight.

EXAMPLE 2 59.6 parts of the dyestuff powder obtained according toExample 1, paragraph 1, are mixed at temperatures of 85 to 90 C. with250 parts of dry pyridine. Subsequently 7.4 parts of urea and 42 partsof amidosulfonic acid are added and heated for 30 minutes to 100 to 105C. The mixture is then introduced into 2500 parts of water and thedyestuir is isolated by salting out with potassium chloride. Thedyestuif which has precipitated is filtered off and the filtrationresidue is washed with potassium chloride of of weight.

The product obtained corresponds to the dyetufi obtained by means ofesterification in concentrated sulfuric acid as described in Example 1.

EXAMPLE 3 141 parts of 1-(4' 9-hydroxyethylsulfonylphenyl)-3-methyl-S-pyrazolone are introduced at temperatures of 25 to C. into 350parts of sulfuric acid of 96% of weight and the whole is stirred at roomtemperature until dissolved completely. Subsequently ice is added andthe solution is neutralised by addition of solid sodium carbonate.

151.5 parts of 2-naphthylamine-1.S-disulfonic acid are diazotised asusual. To the thus obtained suspension of the diazonium salt theabove-mentioned solution of the sulfuric acid ester of1-(4-fl-hydroxyethylsulfonylphenyl) 3-methyl-5-pyrazolone is added. Byfurther adding sodium 4 carbonate the coupling is completed in a weaklyacid to neutral medium. The dyestuif isolated by salting out withpotassium chloride is identical with the dyestutf obtained according toExample 1.

EXAMPLE 4 111.5 parts of 2-naphthylamine-l-sulfonic acid are diazotisedin the usual manner and coupled with 141 parts of1-(4-B-hydroxyethylsulfonylphenyl)-3-methyl-5-pyrazolone' according tothe process described in Example 1. When the coupling is completed thedyestuif which has formed is separated by means of potassium chloride,isolated. by filtration, subsequently dried and pulverised. The productobtained is then esterified according to the process described inExample 1. 400 parts of a yellow powder are obtained, which dissolves inwater producing a yellow color.

. Native and regenerated cellulose fibers are dyed in long dyeing bathsin the presence of alkalis, exhibiting strong and clear greenish yellowtints. The dyeings have good fastness to rubbing, wetting and excellentfastness to light.

EXAMPLE 5 151.5 parts of 2-naphthylamine-1.7-disulfonic acid arediazotised in the usual manner and coupled with 1- (4'13-hydroxyethylsulfonylphenyl) 3 methyl 5 pyrazolone. The dyestutf obtainedis prepared as described in Example 1 and esterified in concentratedsulfuric acid. 470 parts of a yellow water-soluble powder are obtained.The dyestutf which in the form of its free acid corresponds to thefollowing formula produces in the presence of alkalis on native andregenerated cellulose fibers strong, clear greenish yellow tints whichare distinguished by good fastness to wetting and rubbing as well as byexcellent fastness to light. When instead of 151.5 parts of2-naphthylamine-1.7-disulf0nic acid 191.5 parts ofZ'naphthyIamine-1.5.7-trisulfonic acid are used, a dyestuff of similarlygood fastness properties is obtained.

We claim:

1. The water-soluble monoazo dyestufls of the formula SOs-CHz-CHz-O-SOQCin which X represents a member selected from the group consisting ofhydrogen and an alkali metal atom, It stands for one of the numbers 0, 1and 2 and A represents lower alkyl.

